Abstract
Purpose :
Myo/Nog cells, identified by their expression of the skeletal muscle specific transcription factor MyoD, the bone morphogenetic inhibitor Noggin and cell surface protein recognized by the G8 monoclonal antibody (mAb), are present throughout the eye. These cells are critical for normal eye development and quickly respond to wounding in the adult lens and retina. In the lens, Myo/Nog cells are a source of contractile myofibroblasts that contribute to the fibrotic form of posterior capsule opacification (PCO), a vision impairing condition that may occur after cataract surgery. In this study, we examined whether Myo/Nog cells may migrate between the ciliary body and lens on the zonules which hold the lens in place and transmit the force that alters the shape of the lens during accommodation.
Methods :
Whole eyes or the anterior segments of the eyes from mice, rabbits and humans were fixed, embedded in paraffin and sectioned. Some sections were from rabbit eyes that had undergone cataract surgery. Tissue sections were immunofluorescently labeled with antibodies to G8, Noggin and alpha smooth muscle actin (α-SMA).
Results :
Myo/Nog cells were present in the ciliary body and anterior, equatorial and bow regions of the lens in mice and humans. A few Myo/Nog cells were found on the zonules at various distances from the ciliary body. One month following cataract surgery in the rabbit, Myo/Nog cells overlaid wrinkles on the capsule. Myo/Nog cells also were observed on the zonules and within the ciliary body. Some Myo/Nog cells on the zonules expressed the myofibrobast marker α-SMA.
Conclusions :
Myo/Nog cells appear to migrate on the zonules. It remains to be determined whether Myo/Nog cells originating in the ciliary body actually penetrate the lens capsule and if their migration is bidirectional. The possibility that the ciliary body is a source of Myo/Nog cells in the lens should be considered when designing therapeutic approaches that target these cells to prevent PCO.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.